Yellow azo dyestuffs



19,349/43, are mixed with 100 parts of water, 15Y

parts of 32% aqueous sodium hydroxide solution and 15 parts of sodium sulphide crystals. The

mixture is boiled for half an hour. The solutionv of the sodium salt of the resulting mercaptanis cooled. 60 parts of methyl iodide are added with vigorous agitation. A glutinous brown precipitate forms. The mixture is heated during 1/2 hour to 90 C. by which time the precipitate has solidified.

It is filtered olf, and constitutes the methyl esterv of the aforesaid mercaptan. For the sake ofpurication it is made into a paste with alcohol, placed upon a lter and washedwith further alcohol. Finally it is washed free from alkali with water, and dried. The yield is 12 parts.

1 part of the dyestuff so obtained is dissolved in 1500 parts of water at 30 C.` 50 parts of bleached cotton yarn are introduced into the solution. The temperature is raised to 60 C. and maintained thereatrfor 30 minutes. 0.5 part of soda ash is now added and the dyeing is continued for a further 15 minutes at 60 C. The cotton is removed, rinsed with `water and dried. It is bright reddish yellow in shade. The dyeing possessesY good fastness to washing and open soda boiling being similar to that of dyeingsof CaledonYellow G (Colour Index No. 1241).

Example 2 V5 partsV of di(methylmercaptomethyl) 4:4'di (benzthiazyl-2) -azobenzene- (made as described below) are heated with 36Iparts of dimethyl sulphate at 160 C. forV half an hour. The mixture is then cooled and poured into acetone. The precipitated ternary sulphonium salt is ltered off, washed Vwith acetone and dried in the air. A pale yellow powder is obtained. It dyes cotton a yellow shade using a dyebath containing a mild alkali as described in Example 1.

The di(methylmercaptomethyl) 4:4' dibenzthiazyl-2-azobenzene employedV above is made as follows: 5 parts of di(chloromethyl)r4:4' -di- (benzthiazyl-Z)-azobenzene are mixed with 80 parts of v-ethoxyethanol. 1.5 parts of sodium methylY mercaptide are added, the mixture is heated to 11G-115 C. and maintained at this temperature for two hours. tained is poured into' 316 parts of ethanol and stirred vigorously for four hours, filtered and th'e lter-cake is washed with ethanol and then with water. The product is dried in the air. A bright yellow powderisobtained.

Example 3 The mixture obmethylbenzthiazyl 2) azobenzene employed above is made by the method described in Example 2 for the preparation of di(methylmercap tomethyl) -4 :4' -di (benzthiazyl-2) -azobenzene.

Example 4 5. parts of di methylmercaptomethyD -4:4'di -ethoxybenzthiazyl 2) azobenzene (made as described below) are heated with 36 parts of dimethyl sulphate at 115-120n C. for two hours. The so obtained solution is cooled and poured into 200parts of acetone. The precipitated ternary sulphonium salt is ltered off, washed with acetone and dried in the air. A dull yellow powder is obtained, which when dyed on to cotton by the same process as that described in Example 1 gives a yellow shade.

The di(methylmercaptomethyl) 4:4' di(6 ethoxybenzthiazyl-2)-azobenzene employed in the above example may be made as follows:

5 parts of di(chloromethyl)4:4di(6ethoxy benzthiazyl-Z) -azobenzene are mixed with parts of -ethoxyethanol. 1.5 parts of sodium methyl mercaptide are added, the mixture is heated to 11G-115 C. and maintained at this temperature for two hours.

Thev product is poured into 1,000 parts of slightly acidifled water and the mixture is stirred for four hours, then filtered and the lter-cake is washed with water. The product is dried in the air and consists of bright yellow powder.

Eample 5 5 parts of di(ethylmercaptomethyl)4:4di (6-methylbenzthiazyl-2)-azobenzene (made as described below) are heated with 36 parts of dimethyl sulphate at Sil- C. for half an hour. The mixture is cooled and poured into acetone. The precipitated ternary sulphonium salt is filtered off, washed with acetone and dried in the air. Theproduct obtained can be used to dye cotton in a yellow shade, as described in Example 1.

The di(ethylmencaptomethyl) -4 4-di (S-methylbenzthiazyl-Z) -azobenzene employed above may be made as follows: 2 parts of sodium are dissolved in 41 parts of--ethoxyethanol, 5.6 parts of ethyl mercaptan are added and the mixture is stirred. 5 parts of di(chloromethyl)-4:4di(6 methylbenzthiazyl-Z) -azobenzene are then added gradually.Y The mixture is heated under reflux for 2 hours, allowed to cool and poured into 400 parts of ethyl alcohol. Thesuspension is stirred vigorously for four hours. The di(ethylmercap tomethyD-ls/ldi(6methylbenzthiazyl 2)- azobenzene is ltered 01T, washed with ethyl alcohol and then with water; It is dried in the air and consists of lbright yellow powder.

Example 6 V5 parts of di(butylmercaptomethyl)-4:4'di(6 methylbenzthiazyl-Z)-azobenzene (made as described below) are heated with 36 parts of dimethyl sulphate at C. forhalf an hour. The ternary sulphonium salt is isolated 'as described in Example 5. It dyes cotton a yellow shade.

The di (butylmercaptomethyl) -4:4di (f5-methylbenzthiazyl-2) -azobenzene employed above may be made as follows; 2 parts of sodium are dissolved in 41 parts of -ethoxyethanol, 6.8 parts of butyl mercaptan are added and the mixture is stirred. 5 parts of di(chloromethyl) 4:4'di(6 methylbenzthiazyl 2) azobenzene are added gradually to the mixture. It is then heated under reux 'for two hours. The product is isolated as described in Example 5. A yellow powder is obfate is cli-(methyl mercapto)-ch1oro-4,4-di(6 tained. methylbenzthiazyl-2) -azobenzene l Example 7 3. The process in accordance with claim 1 in which the compound mixed with the di-alkyl sul- 5 parts of di(benzylmercaptomethy1)-424-di 5 fate is di-(methylmercaptomethyl)4,4di(6- (-methylbenzthiazyl-Z) -azobenzene (made as methylbenzthiazyl-Z) -azobenzenedescribed below) are heated with 36 parts of diy4. A di-methosulfate of an azobenzene made methyl sulphate at 90-95 C. for half an hour. by making a mixture of a dialkyl sulfate having The solution so obtained is :cooled and poured into 1 to 4 carbons and a compound of the group con- 200 parts of acetone. The precipitated ternary 10 sis'ting of the chloro derivative of di-(methylrnersulphonium salt is filtered off. It dyes cotton in capto) -4,4-di(-methylbenzthiazyl) -(2) -azobena. yellow shade by the process described in EX- zenewhich contains 1.3. atoms of chlorine per ample 1. molecule and the compounds represented by the The di benzylmercaptomethyl 4:4 di(6- formula methylbenzthiazyl 2) azobenzene employed 20 in which X is one of the group consisting of hyabove may be made as follows: 2 parts of sodium drogen, methyl and methoxy, and Y is one of are dissolved in 41 parts of -ethoxyethanol. the ygroup consisting of alkyl having 1 to 4 car- 10.82 parts of benzyl mercaptan are added and bons and benzyl, and heating the mixture at rethe mixture stirred. 5A parts of di(chloromethyl) action temperature until there is formed the cor- 'j 4:4-di(6methylbenzthiazyl 2)- azobenzene. are 25 responding di-rnencaptomethosulfate.Y added gradually. The mixture is stirred under l5". A compound represented by the formula X- s T S.-V X-Il- CH I TCH-e (IPSOS-CH3 2 reux for two hours. The product is isolated as wherein X is one of the group consisting of hydescribed in Example 5. A yellow powder is obdrogen, methyl and methoxy; and Y is one of tained. the group consisting of alkyl having 1 to 4 car- We claim: 35 bons and benzyl. 1. The` process of manufacturing a di-metho- "6. The chloro derivative of the compound repsulfate of an azobenzene which comprises making resented by the formula a. mixture of a di-alkyl sulfate having 1 to 4 which contains 1.3 atoms of chlorine per molecule.

carbons and a compound of the group consisting 7. The compound represented by the formula Haos sons-I I \C @N=N @C =VCH. S=.CH, V Y \'N- (S-SOa-CHa-L of the chlore derivative of di-cmethylmercapto) Y Noni/'LAN HULTON HADDOCK.

4,4di(6methylthiazyl)-(2) -azobenzene which CLIFFORD WOOD. contains 1.3 atoms of chlorine per molecule and the compounds represented by the formula xs s- X-lll Y \O-C -N=No/ :cnrs-Y I rflL l Y 2 in which X is one of the group consisting of hy- REFERENCES CITED drogen, methyl and methoxy, and Y is one of the 0. group consisting of alkyl having 1 to 4 carbons hf fligwggeeens are-gf recrd in the and benzyl; and heating the mixture at reaction temperature until there is formed the correspond- UNITED STATESl PATENTS ing methyl methosulfate. Number Name Date Y 2. The process in accordance with claim 1 in '05V 2363 657 Haddock .Feb 6 1945 WhiCh the Compound mixed With the (ii-alkyl Sul- Haddock 6 1945 2,384,283 Conrad et al.. Sept-1, 1945 

